Drafting machine



C. W. REED AFTING MACHINE Oct. 23, 1951 Filed Sept. 2l, 1948 6. INVENToR.

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Patented Oct. 23, 1951 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to improvements in drafting or drawing machines for use on drawing boards, tables, layout machines and the like, and the primary object of the invention is to provide a more flexible, adaptable and versatile device of this kind which can be more easily and efflciently operated by a draftsman.

Another important object of the invention is to provide an improved drafting machine of the character above indicated in which the protractor element is operable by worm Vernier means, which is readily disengageable to permit the draftsman to manually move the protractor to a selected position when desired, and which is reengageable to permit Vernier adjustment of the protractor relative to such' position.

Another important object of the invention is to provide a drafting machine of the character indicated above featuring a guide rail and supporting means therefor, permitting easier and more exact mounting of the machine on the drafting table or board, and permitting the movable assembly of the machine to be shifted the full length of the rail or width of the table or board carrying with it a transparent edge straight edge; and said supporting means involving means enabling said movable assembly to be adjusted easily and accurately to the desired height so that the straight edge will have proper board clearance; and said supporting means further including eccentric compensating means facilitating alignments when replacing tracings or drawings and eliminating repeated re-pinning of such drawings and tracings.

Another important object of the invention is the provision in supporting means of the char: acter indicated above of an adjustable tension keeper roller arrangement for holding the roller means engaged with the opposite side of the rail. vAnother important object of the invention is to provide a drafting machine of the character indicated above in which the rail is round or cylindrical, whereby the movable assembly of the machine can be rotated on the axis of the rail into a vertical position relative to a horizontal table or board, thereby freeing the table or board of any obstruction otherwise resulting from the presence of the drafting machine.

Other important objects and advantages of the invention will be apparent from the following descriptionv and accompanying drawings, wherein, merely for purposes of illustration, a presentlypreferred embodiment of the invention is set forth detail.

In the drawings:

Figure 1 is a contracted top plan view of said embodiment.

Figure 2 is a fragmentary vertical longitudinal section taken on the line 2 2 of Figure 1.

Figure 3 is a transverse section taken on the line 3-3 of Figure 1, and,

Figure 4 is a longitudinal section through the Vernier device.

Referring in detail to the drawings, thefnumeral 4 generally designates a drawing or drafting table or board, here shown as horizontally arranged, with which the machine, generally designated 5, embodying the present invention is shown as associated.

The machine 5 comprises a pair of brackets 6, 6 spaced along the adjacent edge of the board 4, each comprising an upper horizontal part 1, engaging the underside of the drawing board VI and traversed by mounting screws 8, 8, a depressed horizontal part 9, in which is vertically threaded a rail-supporting and adjusting screw I!) having a reduced stud I I on its upper end slidably traversing the horizontal tubular cylindrical or round rail I2, and a knob or handhold I3 on its lower end. The brackets 6 support the round rail I2 below and generally parallel with the adjacent edge I4 of the board 4, as shown in Figure 2. The foregoing constitute the stationary assembly of the machine 5.

The movable assembly of the machine 5 comprises the horizontal semi-circular plate I5 from whose inner edgedepend a number of grooved vertical axis rollers I6, in this case two such rollers, for rollably engaging the inner side of the round rail I2, which rollers I6 are opposed by one or more keeper roller assemblies I1, whereby the rollers I6 are kept engaged with the rail I2, and whereby the entire movable assembly can, from the point of view of Figure 2, be rotated on the axis of the rail I2 in a counterclockwise direction into a vertical position in which the top of the board 4 is free of obstruction.

Each keeper roller assembly I1 comprises a bifurcated shaft I8 carrying a plane surface roller I9 in engagement with the rail I2 and horizontally slidably traversing spaced ears 20, 20 on a bracket 2I in the form of a clevis depending from the bed plate I5, with a nut 22 threaded on shaft I8 between said ears for feeding the roller I9 with the desired tension against the rail I2. As indicated in dotted lines in Figure 1, a single keeper roller I 1 may be used between two grooved rollers I6, I6.

Mounted upon the top of the bed plate I5 by a vertical clamping and pivot stud 26,*,having both ends threaded as indicated at 21 and 28, respectively, and passing upwardly through an accommodating opening in the plate l above the keeper roller I9, are the substantially semi-circular protractor plate 29, the laterally rearwardly-extending straight edge 3Q, and the clamping disc 3|, in the vertical order named from bottom to top. A washer 32 and nut 33 are provided on the lower threaded lend 2T of the stud 26 for engaging the under side of the .bed plate, and a knurled nut 34 is provided on the upper threaded end 23 of said stud for engaging the upper side of the clamping disc 3l.

The bed plate I5 and protractor plate have conventional annular surfaces I5' and 29', respectively, by which they have free rotational bearing upon each other on the axis of the stud 26. The protractor plate 25 and the straight edge 30, instead of being locked against rotation relative to each other by the usual arrangement oi a plurality of screws having slotted heads, are held against such rotation by asingle dowell pin ,S5 arranged with its head 36 seated in a lrecess in the bottom of the protractor plate and its shank rising into an eccentric accommodating opening provided in the straight edge 30. This arrangement, in conjuction with the provision of the special stud 26 and the knurled nut 34 on its upper end, Aprovides .proper assembled relation of the associated parts, and provides also greater ease of l:

manipulation thereof in the assembling and disfassembling of these parts, and their manipulation in the use ofthe machine than are afforded by the usual slotted head stud and screws, which require a screw driver for loosening and tightening them. rThe stud 28 has a xed shoulder or collar 3l which seats in an accommodating recess -in the top of the protractor plate 29, so that when the straight edge and clamping disc 3l are loosened or removed, the protractor plate 29 retains its initial or original assembled relation with the bed plate l5 determined by the adjustment of the lower nut 33.

The straight edge 30 is preferably of the transparent edge type and has a check rail 38 along the near or lower edge, as indicated in Figure 3.

At the middle of the curved edge of the bed plate I5 is a .pair of depending, outwardly directed lugs 39', 39' through which pointed screws 4W, 40 are threaded, with their pointed ends engaging in tapered holes 4I', 4I' in opposite ends of a depending part 42 on a worm housing 39, including a tubular portion 43 tangential to the periphery of the protractor plate 29 and affording bearing for shaft 4I carrying a worm 42 in mesh with worm teeth 43 on the periphery of the protractor plate 29, The worm 42 is manually operable by aknurled Vernier knob 44 having a cylindrical Gil-graduation scale 45 within a head 4S on the tubular portion 45 formed with an opening 4l exposing the scale, as shown in Figure l. The worm housing 39 includes a thumb lever 4S projecting outwardly therefrom by means of which the worm housing 39 can be swung outwardly on the pivot screws 4E, dil', so as to disengage from the protractor plate teeth 43 at the will of the draftsman to permit manual rotation of the `protractor free of the worm, enabling the draftsman to manually set the protraotor in a desired position, and thereafter re-engage the worm 42 with the protractor teeth 43 and operate the Vernier knob 44 and obtain a Vernier adjustment of the protractor.

The depending portion 42 on the worm housing 3S has a laterally inwardly-projecting arm 25 which reaches under the bed plate I5, as shown in Figure 2, and is downwardly tensioned to hold the worm 42 engaged with the protractor teeth 43 by a downwardly spring-pressed plunger 24, mounted in a vertical tubular boss depending from the bed plate.

A rim portion 29 on the bed plate I5 has an inwardly-projecting pointer 45, bent to conform to the angulated scale portion 50 of the protractor plate 29, as shown in Figure 2, the pointer 49 being carried on a removable plate 49' secured by ,screws 50' to the rim portion 29.

'The stud II of one of the mounting screws I0 is eccentric with respect to the longitudinal axis of thescrew, as indicated in dotted lines in Figure 1, whereby the rail I2 can be shifted toward andaway from .the adjacent edge I4 of the board 4 by turning the knob I3 in opposite directions.

`On the remote end of the rail I2 is provided a grooved pulley arrangement comprising a collar 52 encircling the rail I2 including a lock-ing thumb set screw 53 which acts as axle for the grooved pulley54, a washer 55 being placed .between the outer side of the pulley and the handhold `56, as shown in Figure l.

It will be observedthat the fact that the brackets 6 do not interfere at any stage with the freedom of movement of the movable assembly of the machine along the rail I2, the rail I2 may be made considerably longer than the drawing board i when desired, so that the movable assembly can in that case be moved along the rail to a position in which the straight edge 30 is carried Voff and clears either .end of the drawing board.

I claim:

l. A drafting machine adapted to be 'mounted along an edge of a drawing board, comprising bracket means for attachment to spaced points along said edge of the drawing board, a 4rail supported on said lbracket means, a bed plate `having depending vertical axis stationary rollers cngaging one side of said rail, at least one .tensioning roller depending from said bed plate 'between said stationary rollers and engaging the opposite side of said rail whereby said bed plate is mounted on said rail to move therealong and swing upwardly with respect to the drawing board, a protractor cluding a straight edge to overlie the drawing board, vertical pivot means mounting said protractor on said bed plate, said bracket means comprising vertically adjustable screws engaging said rail and being operable to raise and lower said rail protractor and straight edge relative to said drawing board, one of said screws having a reduced eccentric stud on its upper end supportably journalled in said rail whereby rotation of said one screw in opposite directions adjusts said rail toward and away from the edge of the drawing boardl 2. In a drafting machine adapted to be mounted along an edge of a drawing board, a pair of brackets adapted to be secured to the underside of the drawing board having terminals projecting beyond the drawing board edge and below the level of the drawing board, said terminals being spaced apart along the drawing board edge, vertical adjusting screws traversing said terminals having upper ends rising above said terminals, reduced studs on the upper ends of said screws, a rail supported on the upper ends of said screws on a level below the drawing board, said rail being formed with vertical journal holes journalling said studs, a bed plate having depending vertical axis stationary rollers engaging the side of said rail adjacent to the drawing board edge, said bed plate having depending tensioning roller means engaging the opposite side of said rail and located between said stationary rollers whereby said bed plate is supported on said rail for movement in opposite directions along the drawing board edge, said stationary rollers and said tensioning roller means being arranged to support said bed plate at a level below the top of the drawing board, a protractor plate rotatably engaging the top of said bed plate and pivoted on a vertical axis thereon, the top of said protractor plate being on a level not substantially higher than the top of the drawing board, and a straight edge mounted upon said protractor plate to extend over the drawing board.

3. A drafting machine adapted to be mounted along an edge of a drawing board, comprising a pair of brackets adapted to be secured to the underside of the drawing board having terminals projecting beyond the drawing board edge, said terminals being spaced apart along the drawing board edge and depressed below the level of the drawing board, vertical adjusting screws traversing said terminals, reduced studs on the upper ends of said screws, a rail supported on the upper ends of said screws, said rail being formed with vertical journal holes journalling said studs, a bed plate having depending vertical axis stationary rollers engaging the side of said rail adjacent to the drawing board edge. said bed plate having depending tensioning roller means engaging the opposite side of said rail and located between said stationary rollers whereby said bed plate is supported on said rail for movement in opposite directions along the drawing board edge, said stationary rollers and said tensioning roller means being arranged to support said bed plate at a level below the top of the drawing board, a protractor plate rotatably engaging the top of said bed plate and pivoted on a vertical axis thereon, the top of said protractor plate being on a level not substantially higher than the top of the drawing board, a straight edge mounted upon said protractor plate to extend over the drawing board, the stud on one of said adjusting screws being eccentrically arranged whereby rotation of said one adjusting screw in opposite directions swings said rail toward and away from the drawing board edge on the axis of the stud of the other adjusting screw.

4. A drafting machine adapted to be mounted along an edge of a drawing board, comprising a pair of brackets adapted to be secured to the underside of the drawing board having terminals projecting beyond the drawing board edge. said terminals being spaced apart along the drawing board edge and depressed below the level of the drawing board, vertical adjusting screws traversing said terminals, reduced studs on the upper ends of said screws, a rail supported on the upper ends of said screws, said rail being formed with vertical journal holes journalling said studs, a bed plate having depending vertical axis stationary rollers engaging the side of said rail adjacent to the drawing board edge,said bed plate having depending tensioning roller means engaging the opposite side of said rail and located between said stationary rollers whereby said bed plate is supported on said rail for movement in opposite directions along the drawing board edge, said stationary rollers and said tensioning roller means being arranged to support said bed plate at a level below the top of the drawing board, a protractor plate rotatably engaging the top of said bed plate and pivoted on a vertical axis thereon, the top of said protractor plate being on a level not substantially higher than the top of the drawing board, a straight edge mounted upon said protractor plate to extend over the drawing board, said tensioning roller means comprising a clevis depending from said bed plate having laterally spaced legs, a threaded shaft slidably traversing said legs, a vertical axis roller on said shaft at one side of said clevis and engaging the said opposite side of the rail, and a nut threaded on said shaft between said legs and adapted to be turned in opposite directions to extend and withdraw said roller relative to said rail.

CLIFFORD W. REED.

REFERENCES CITED The following references are of record in the lle of this patent:

UNITED STATES PATENTS Number Name Date 5025112 Bramwell July 25, 1893 658,262 Hester Sept. 18, 1900 713,255 Traut Dec. 16, 1902 1,031,665 Pocklington July 2, 1912 1,042,743 Wuest Oct. 29, 1912 1,050,605 Boland Jan. 14, 1913 1,116,231 Bramwell Nov. 3, 1914 1,147,105 Lederer July 20, 1915 1,229,069 Hagman June 5, 1917 1,351,527 Lopez Aug. 31, 1920 1,382,460 Berglof June 21, 1921 1,459,792 Nilant June 26, 1923 2,077,677 Dawson et al.A Apr. 20, 1937 2,243,838 Cunningham June 3, 1941 2,443,364A Vancura June 15, 1948 2,471,099 Dethlefs May 24, 1949 FOREIGN PATENTS Number Country Date 241,384 Germany Jan. 17, 1911 367,673 Germany Jan. 26. 1923 

